A.I. needs to be more accurate. Does the pilot see the other planes on the paths to runways or not? I know that we are on times with many suicide-attacks but here... And there is no clearance at all from the control tower. They land but automatically. That's the first job of the aerial controllers: giving clearances!
I suggest you to add some shapes or rooms to the tower the more you improve your abilities. I remember HOMM and the city upgrades :D
Very good game indeed
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 "Airport Madness World Edition"){kind=icon}
 "The Perfect Tower"){kind=icon}